In two days near Manali, you can cover Hadimba Temple, Old Manali, Vashisht Temple, and Mall Road on the first day. These spots are close and easy to explore.
On the second day, visit Solang Valley and, if conditions allow, Atal Tunnel and Sissu for scenic views.
With good planning and a Delhi to Manali Tempo Traveller Package, these places can be covered comfortably in a short trip.
check - https://delhitempotravels.com/delhi-to-manali-tempo-traveller.html